1. Field of the Invention
This invention concerns the field of reaction injection molded elastomers.
Reaction injection molded elastomers make excellent molded parts useful, for example, in the automobile industry as exterior parts for vehicles.
2. Description of Related Publications
U.S. Pat. Nos. 4,396,729; 4,444,910 and 4,433,067 concern elastomers prepared using a high molecular weight amine terminated polyether, an aromatic diamine chain extender and an aromatic polyisocyanate which may merely be a polyisocyanate or a quasi-prepolymer prepared from a polyol reacted with a polyisocyanate wherein some isocyanate groups are still left unreacted. Various patents have been applied for and received using the basic combination recited above as well as various mold release agents and other additives, for example, catalysts.
U.S. Pat. 4,585,850 concerns and claims a reaction injection molded elastomer made by reacting in a closed mold amine terminated polyethers of greater than 1500 average molecular weight, having greater than 50% of their active hydrogens in the form of amine hydrogens, a chain extender, flaked glass pretreated with amino silane coupling agent, and an aromatic polyisocyanate. The U.S. Pat. No. 4,585,850 referred to above contains a discussion of other applications and patents in the field and is incorporated herein by reference.
European Patent Application No. 81,701A concerns reaction injection molded elastomers where fatty acid salts are recommended internal mold release agents. The corresponding U.S. application Ser. No. 443,444, filed 11/22/82, now abandoned is the subject of interference proceedings with the U.S. Pat. Nos. 4,396,729, 4,444,910 and 4,433,067 referred to above (Interference Nos. 101,393; 101,394; and 101,395).
An article in Plastics Engineering (May 1978) by John Foley of Witco Chemical Corp. discusses the use of surfactants as internal mold release agents.
C. A. 103:55263p, Asahi Glass Co. Ltd. (Japan) discusses mold release agents in microcellular urethane elastomers.
C. A. 103:38515e, Jpn. Kokai Tokkyo Koho JP 60 81,220 (85 81,220) Asahi Glass Co. Ltd. (Japan) discusses nonionic surfactants as internal mold release agents for polyurethane elastomers.
We have found that many advantages can be obtained by an additive to be discussed below which is an amine based on a mixture of alkylene oxides.